Deck paint can be either oil-based or acrylic — both are good products. Oil-based paint has the advantage of being slower-drying, which makes outdoor application easier and more mistake-free. Acrylic paints have less VOCs and clean up easier. Another option is solid color stains.
A pergola should be painted with acrylic paint since it is weather-resistant and long-lasting. When the humidity is very low, oil-based paints are best applied during the driest season.
Yes, absolutely. No matter what you have, you can shoot either a base coat or a clear coat. In the case of a tight-air compressor, I would recommend installing the LVLP. You want to do your best in terms of technical use; HVLP spray guns will be more suited for base coats and LVLP spray guns for cle...